Abstract: The invention relates to method and apparatus for running a plurality of interrelated computational tasks on a plurality of host computers. The host computers run a primary operating system. The method includes the steps of: establishing a virtual machine running on a host computer where the virtual machine is configured to run as a native application emulating a secondary operating system including storage and I/O functionality. The virtual machine may be configured to provide the host computers primary operating system with access to the virtual machines secondary operating system and the virtual machine with access to the host computers system resources. The virtual machine may also emulate a file system by providing a guest file system and provide access to the host computers system resources via a host system call converter. Virtual machine system calls are converted to the host systems system calls by a host system call converter and controls the access to the users system resources.